In the first decade of numbers (1-10), there are four prime numbers (2,3,5,7). In the second decade (11-20), there are another four (11,13,17,19).

Are there other such decades with four prime numbers?

(In reply to re(2): spoiler -- more by Paddy)

The language is UBASIC.  It features extended precision (thousands of decimal places) and as in this example, nxtprm and similar functions.  The interpreter is available on the internet.

Posted by Charlie on 2006-11-18 16:36:09